1. Field of the Disclosure
The disclosure relates to a bump structure and an electronic packaging solder joint structure and a fabricating method thereof. Particularly, the disclosure relates to a bump structure used to form an intermetallic compound, and an electronic packaging solder joint structure having the intermetallic compound and a fabricating method thereof.
2. Description of Related Art
In an electronic packaging process, commonly used solder joints is micro solder joints. The bonding method of the micro solder joints mainly uses an eutectic bonding and is an irreversible chemical reaction. Intermetallic compound (IMC) is formed by an interreaction between a part of the metal and the solder in the solder joint after eutectic bonding.
Because a general micro solder joint has a less content of the IMC therein, the micro solder joint has better flexibility and toughness, which leads to better capability in anti-mechanical stress, though the micro solder joint has a poor capability in anti-electromigration (EM).
In a situation of increasing heating time or temperature on purpose, or after a temperature cycling reliability testing process, the micro solder joint forms a great content of the IMC very fast due to a high temperature, and the solder has be totally transformed to the IMC. The micro solder joint having the great content of the IMC has hardness higher than that of the original micro solder joint, which has higher rigidity and is lack of flexibility, so that the micro solder joint having the great content of the IMC is liable to be damaged in the temperature cycling reliability testing process. However, the micro solder joint has a characteristic of mitigating an electromigration effect by increasing the content of the IMC.
Therefore, an electronic packaging solder joint structure having both of the characteristics of anti-mechanical stress and anti-electromigration effect is required to be developed, so as to improve reliability and performance of the solder joint.